Surface-enhanced Raman spectroscopy for the in vitro and ex vivo detection of excitatory amino acids

Traditional methods for the detection of excitatory amino acids, which have been linked to secondary injury following head trauma, can be excessively time consuming clinically. A near real-time measurement system could provide clinical information in anticipation of pharmaceutical intervention for head injured patients. Our studies have shown that Surface-Enhanced Raman Spectroscopy (SERS) with silver colloids has the ability to measure physiological concentrations of in vitro excitatory amino acids using short scan times. Employing a damage model for ischemia, preliminary ex vivo rat extracellular brain fluid analysis shows an intriguing correlation between SERS spectral features and expected Glutamate concentration fluctuations following head injuries.